US20020064150A1 - System and method for diagnosing a POTS port - Google Patents
System and method for diagnosing a POTS port Download PDFInfo
- Publication number
- US20020064150A1 US20020064150A1 US09/948,387 US94838701A US2002064150A1 US 20020064150 A1 US20020064150 A1 US 20020064150A1 US 94838701 A US94838701 A US 94838701A US 2002064150 A1 US2002064150 A1 US 2002064150A1
- Authority
- US
- United States
- Prior art keywords
- iad
- pulsing
- indicia
- tip
- hallmark
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L43/00—Arrangements for monitoring or testing data switching networks
- H04L43/50—Testing arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
- H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
- H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor
- H04M3/30—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor for subscriber's lines, for the local loop
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/2209—Arrangements for supervision, monitoring or testing for lines also used for data transmission
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M7/00—Arrangements for interconnection between switching centres
- H04M7/006—Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP), including next generation networks with a packet-switched transport layer
Definitions
- This invention relates generally to Voice-over-Broadband (VoB) communication systems, and particularly to diagnostic assessments of the integrity of VoB systems.
- VoB Voice-over-Broadband
- FIG. 1 shows a prior art VoB system 100 , which commences at one end with traditional Plain Old Telephone Service (POTS) devices 110 that receive and transmit analog voice signals over subscriber lines 115 .
- POTS Plain Old Telephone Service
- An Integrated Access Device (IAD) 130 digitizes/packetizes these analog voice signals into a broadband format and integrates the resultant voice packets with additional digital data provided by other customer premise equipment such as personal computer 120 .
- IAD 130 prioritizes voice packets over data packets to preserve transmitted voice signal quality.
- the voice and data packets are carried over the local broadband access network to an access multiplexer known as a Digital Subscriber Line Access Multiplexer (DSLAM) 140 .
- DSLAM Digital Subscriber Line Access Multiplexer
- DSLAM 140 aggregates the packets, transports voice packets to a voice gateway 150 and transports data packets to the Internet 160 .
- Voice gateway 150 depacketizes voice packets and converts them to standard analog POTS signals for delivery via a Class 5 switch 165 to the Public Switched Telephone Network (PSTN) 170 .
- PSTN Public Switched Telephone Network
- FIG. 2 shows details of IAD 130 .
- a POTS device 110 connected to the subscriber's line 115 is in turn connected with a Subscriber Line Interface Circuit (SLIC) 210 .
- the SLIC 210 has inputs for a primary battery supply (VBAT1) 220 and an auxiliary battery supply (VBAT2) 230 , and has a battery switching circuit 373 (FIG. 5) for connecting to VBAT1 220 to present a high on-hook voltage, and then connecting to VBAT2 230 to present a low off-hook voltage in short-loop applications.
- VBAT1 and VBAT2 are connected in series by a diode 225 .
- the diode serves as a protection device to prevent the VBAT1 ( ⁇ 68V) supply from going more positive than the VBAT2 ( ⁇ 24V) supply. This would happen if the VBAT1 supply failed, since VBAT1 voltage ( ⁇ 68V) is obtained by adding a ⁇ 44 voltage to the VBAT2 supply.
- SLIC 210 passes analog POTS signals to a coder/decoder (CODEC) 240 and receives analog signals from CODEC 240 .
- CODEC 240 converts analog voice signals into broadband digital format, and vice versa.
- IAD 130 can include a digital signal processor (DSP) 250 for removing noise from the digital signals.
- DSP digital signal processor
- IAD 130 employs a microprocessor controller (MPC) 260 as a central software-driven controller.
- MPC microprocessor controller
- MPC 260 can manipulate digital signals as necessary per the instructions of an installed software application, can receive state information from the various IAD 130 components, and can send digital control signals to the other components of IAD 130 .
- MPC 260 sends digital control inputs 270 to SLIC 210 , which control internal SLIC states.
- FIG. 2 shows only one POTS port and only the processing of voice data.
- an IAD 130 also processes incoming digital data and includes multiple ports (typically in RJ-11 format) for connecting multiple POTS devices 110 .
- the IAD 130 is a critical component of a VoB system.
- IAD equipment will proliferate and it will become more important that VoB service providers have the ability to efficiently and cost effectively maintain IADs.
- VoB service providers give useful customer support regarding the low technology POTS devices.
- POTS devices rely on a simple two-wire loop for all their power and signaling needs and do not provide any diagnostic signaling.
- VoB communications for diagnostic tests on IAD equipment and POTS devices that do not require additional hardware modifications and associated costs (i.e., abide by the constraints of existing hardware designs) and do not require physical site visits for the purpose of conducting the diagnostic tests.
- the invention encompasses a method for diagnosing Voice-over-Broadband circuitry including an Integrated Access Device.
- the method includes receiving a request to initiate diagnosis, pulsing source voltages of tip and ring amplifiers in the circuitry, aggregating signal line noise resulting from the pulsing, analyzing the aggregated noise for hallmark indicia, and reporting findings of the analysis.
- a system in accordance with the invention remotely diagnoses Voice-over-Broadband circuitry by pulsing the source voltages of the tip and ring amplifiers in the circuitry and analyzing the resultant noise for hallmark indicia.
- the system comprises a broadband line and an Integrated Access Device connected to the broadband line.
- the Integrated Access Device includes a controller connected to the broadband line, a coder/decoder connected to the controller, a Subscriber Line Interface Circuit connected to the coder/decoder, primary and auxiliary power sources connected to the Subscriber Line Interface Circuit, a Plain Old Telephone System port connected to the Subscriber Line Interface Circuit, and a signal line which interconnects the broadband line, controller, coder/decoder, Subscriber Line Interface Circuit, and Plain Old Telephone System port.
- the Subscriber Line Interface Circuit has tip and ring amplifiers and a switching circuit for pulsing the source voltage of the tip and ring amplifiers.
- the controller executes software to control the switching circuit into pulsing the source voltages of the tip and ring amplifiers in accordance with the invention.
- FIG. 1 is a high-level view of a prior art voice-over-broadband architecture
- FIG. 2 shows additional detail of a prior art IAD
- FIG. 3 shows hardware aspects of the present invention
- FIG. 4 shows detail of the SLIC of FIG. 3
- FIG. 5 is a voltage versus time graph that traces the frequency sweep pulse characteristics of one embodiment of the invention.
- FIG. 6 is noise plot for a first embodiment of the invention when a POTS device is connected to the IAD;
- FIG. 7 is a noise plot for a first embodiment of the invention when no POTS device is connected to the IAD;
- FIG. 8 is a voltage versus time graph that traces the fixed period pulse characteristics of a third embodiment of the invention.
- FIG. 9 is a noise plot for a third embodiment of the invention when both power supplies are functional and a POTS device is connected to the IAD;
- FIG. 10 is a noise plot for a third embodiment of the invention when both supplies are functional and no POTS device is connected to the IAD;
- FIG. 11 is a noise plot for a third embodiment of the invention when the primary power supply is disabled and a POTS device is connected to the IAD;
- FIG. 12 is a noise plot for a third embodiment of the invention when the primary power supply is disabled and no POTS device is connected to the IAD.
- FIG. 3 shows an IAD 130 configuration including a SLIC 210 , a VBAT1 power supply 220 , a diode 225 , a VBAT2 power supply 230 , a CODEC 240 , an optional DSP 250 , an MPC 260 , and digital control inputs 270 .
- MPC 260 is connected to a broadband line 310 , a DSLAM 140 , an RS- 232 port 320 , and an external computer 330 . From a hardware perspective, the invention is similar to, and requires no additional hardware or design modifications over, the FIG. 2 prior art. Thus, the invention addresses the prior art need for efficient maintenance and support of IADs and associated POTS devices.
- External computer 330 is optional and is most likely to be used only to initiate the diagnostic tests. Execution of the diagnostic tests of the invention does not require external computer processing.
- the detailed diagnostic test instructions and the collection and analysis of test data can all be done by a computer software application installed within IAD 130 , preferably within MPC 260 . Thus, the invention can be practiced as a software-only upgrade to the prior art IAD hardware 130 .
- the external computer if used, can be either: (a) located remotely and connected via the broadband line 310 to the IAD 130 ; or (b) located locally and connected via the RS-232 port 320 .
- the technique of the invention pulses the internal IAD DC power supplies (VBAT1 220 and VBAT2 230 ), collects resultant noise signals within the IAD 130 and analyzes the data to determine the status of IAD circuitry and the integrity of connections with POTS devices.
- the noise signals are measured using an AC coupled measuring system originally intended to digitize voice signals on the telephone line and block the VBAT2 battery voltage, which is present in addition to the voice signal.
- the measurements in that embodiment are of the AC transients (or the first derivative) of the DC pulsing.
- DC coupled noise measurements is to the magnitude of the diagnostic threshold values, which will be discussed below.
- FIG. 5 shows high level details of SLIC 210 .
- SLIC 210 communicates analog signals via transmit line 390 and receive line 392 to and from CODEC 240 and communicates via a combined tip 394 and ring 396 loop 115 with a POTS device 110 .
- the tip-ring loop 115 is formed by a POTS device 110 on one end connected via a tip line 394 and a ring line 396 to an appropriate apparatus such as IAD 130 .
- Tip line 394 is referenced against ring line 396 and hence tip-ring loop 115 is considered a two-wire loop.
- transmit line 390 is referenced against a ground line and receive line 392 is also referenced against a ground line.
- a counterpart four-wire conceptual loop (not shown) is formed by the interconnection of: (a) the hybrid circuit 371 ; (b) one pair of wires that represent the transmit line 390 and the ground wire it is referenced to; (c) and another pair of wires that represent the receive line 392 and the ground wire it is referenced to; and (d) a device downstream of the communication path that connects with the four wires.
- the hybrid circuit 371 interfaces a 2-wire loop to a 4-wire loop.
- This 4-to-2 arrangement is backwardly compatible with conventional POTS network architectures, which use a 2-wire loop for local transmission (i.e., near the POTS device) and use a 4-wire arrangement (one 2-wire loop for transmitting and another 2-wire loop for receiving) for long-range transmissions.
- Long-range wire transmissions require signal amplification which is made possible by separation of the receive and transmit analog signals.
- SLIC 210 includes the 4-wire to 2-wire interface in the form of hybrid circuit 371 , which includes Op amps 370 , 372 , and 374 .
- the tip drive amplifier 370 and the ring amplifier 372 have significance to the invention because the supply voltage of these two Op amps is pulsed as discussed below.
- SLIC 210 interfaces via a relay 398 to the tip and ring lines 394 and 396 , respectively.
- the relay 398 disconnects analog voice signals from the POTS device when the POTS device is “on-hook,” and connects the analog signals when “off-hook.”
- the tip-ring loop alternatively connects the POTS device ring detector (not shown) to the IAD 130 .
- SLIC 210 also receives digital MPC control inputs 270 , which control internal SLIC states.
- SLIC 210 includes a battery feed state control circuit 386 , which, per the MPC instructions, controls the switching circuit 373 that receives battery supply voltages VBAT1 220 and VBAT2 230 and feeds the appropriate voltage to the tip drive 370 and ring drive 372 amplifiers.
- Switching circuit 373 has at least three connection states: (a) VBAT1 connection 380 —when VBAT1 is fed to the amplifiers; (b) forward disconnection 382 —when the tip and ring amplifiers are turned off; and (c) VBAT2 connection 384 —when VBAT2 is fed to the amplifiers.
- the invention pulses the source voltage of the tip amplifier 370 and ring amplifier 372 as follows.
- MPC 260 (FIG. 3) executes a software algorithm which sends the necessary control signals on lines 270 to battery feed state control circuit 386 which, based in part on MPC 260 inputs, makes the necessary power switching decisions for the switching circuit 373 to make the appropriate physical connection to feed the tip and drive amplifiers 370 and 372 .
- FIG. 5 is a voltage versus time graph 500 of one such pulse characteristic that can be used to remotely determine whether a POTS device 110 , in an on-hook state, is connected to IAD 130 and whether VBAT2 is functional.
- Graph 500 Y-axis 520 corresponds to the voltage applied to the tip 370 and ring 372 amplifiers during diagnostic tests of the invention, and the graph 500 X-axis 510 corresponds to time.
- the graph 500 voltage cycles have fixed length pulses 550 and increasingly longer cycle periods 540 .
- the voltage applied to the tip 370 and ring 372 amplifiers pulses from a near zero value (obtained by placing SLIC 210 in a forward disconnect state 382 ) to a VBAT2 value 530 .
- the increasingly long cycle periods 540 represent a frequency sweep, which is central to this embodiment of the invention.
- the noise caused by pulsing the amplifiers is aggregated at the CODEC 240 and, according to another aspect of the invention, analyzed by the MPC 260 . Sweeping through a range of frequencies in the AC loading of the ring detector and/or ringer circuit of a POTS device 110 presents a non-linear response at the CODEC 240 .
- FIG. 6 graph 600 has an x-axis 610 , a y-axis 620 , and a series of spikes 630 a through 630 q representing noise data where a POTS device 110 is connected to the IAD 130 .
- FIG. 7 graph 700 has an x-axis 710 , a y-axis 720 , and a series of spikes 730 a through 730 n representing noise data where no POTS device is connected to the IAD 130 .
- the x-axis correlates to time while the y-axis correlates to the magnitude of the noise measured by the CODEC 240 .
- This frequency sweep causes two indicia in the noise response, which the diagnostic algorithm looks for.
- the connection of a POTS device 110 causes noise amplitude to increase as pulse frequency decreases.
- the connection of a POTS device 110 causes FIG. 6 noise spikes 630 a through 630 q that have maximum amplitude below an apparent threshold of approximately 1000 linearized codec counts, while FIG. 7 noise spikes 730 a through 730 n all exceed that threshold by a factor of about 30 .
- the MPC 260 can report that a POTS device 110 is connected to the IAD 130 . Additionally, the MPC 260 can report that VBAT2 230 is also functional.
- FIG. 6 and in FIG. 7 Not shown in FIG. 6 and in FIG. 7 is empirical data dealing with a disabled VBAT2. However, if VBAT2 were not functioning, the peak-to-peak voltage swing would drop below a predetermined threshold value. Thus, a diagnostic algorithm would assess the failure of VBAT2 by noting a peak-to-peak noise measurement that is below a defined algorithm.
- a second embodiment of the present invention is similar to the first embodiment but the DSP 250 , if present, is instructed not to filter out noise. Then, with the POTS device 110 in an on-hook state, the same frequency sweep is remotely executed and the resultant noise is allowed to propagate all the way up to the gateway 150 or even beyond the class 5 switch. At the remote site, presence of the necessary noise indicia indicates that all hardware components up to the SLIC 210 (including VBAT2 230 ) are functional.
- FIG. 8 shows a second pulse characteristic, which can be used to remotely assess some of the functionality in: the IAD batteries 220 and 260 , the SLIC 210 and associated switching circuits 373 and 386 and associated 4-wire to 2-wire hybrid circuit 371 , and the CODEC 240 .
- VBAT1 due to the protection diode between VBAT2 and VBAT1, VBAT1 can not be tested the same way VBAT2 is tested because even if VBAT1 fails, it will still have the VBAT2 voltage level due to the protection diode.
- FIG. 8 is a graph 800 with a y-axis 820 corresponding to the voltage applied to the tip 370 and ring 372 amplifiers during diagnostic testing and with an x-axis 810 corresponding to time.
- the graph 800 pulses have fixed duration cycle periods 840 and fixed duration pulses 850 .
- the voltage applied to the tip 370 and ring 372 amplifiers pulses from a VBAT2 value 830 (obtained by placing the SLIC 210 in a VBAT2 connection 384 ) to a VBAT1 value 835 (obtained by placing the SLIC 210 in a VBAT1 connection 380 ).
- the fixed cycle periods 840 are a central characteristic of this embodiment in contrast to the first and second embodiments where periodicity varies.
- noise is aggregated at the CODEC 240 and analyzed by the MPC 260 .
- FIGS. 9 through 12 provide contrasting examples of empirical data collected in experimental runs of this fixed-frequency embodiment of the invention.
- FIG. 9 is a graph 900 having an x-axis 910 that correlates to time, a y-axis 920 that correlates to resultant noise magnitude, and a series of noise spikes 930 a through 930 n .
- the empirical data of FIG. 9 has both VBAT1 220 and VBAT2 230 in a functional state and a POTS device 110 connected to IAD 130 .
- FIG. 10 is a graph 1000 having an x-axis 1010 that correlates to time, a y-axis 1020 that correlates to resultant noise magnitude, and a series of noise spikes 1030 a through 1030 n .
- the empirical data of FIG. 10 has both VBAT1 220 and VBAT2 230 in a functional state but without a POTS device 110 connected to IAD 130 .
- FIG. 11 is a graph 1100 having an x-axis 1110 that correlates to time, a y-axis 1120 that correlates to resultant noise magnitude, and a series of noise spikes 1130 a through 1130 z .
- the empirical data of FIG. 11 has VBAT1 220 in a disabled state and with a POTS device 110 connected to IAD 130 .
- FIG. 12 is a graph 1200 having an x-axis 1210 that correlates to time, a y-axis 1220 that correlates to resultant noise magnitude, and a series of noise spikes 1230 a through 1230 q .
- the empirical data of FIG. 12 has VBAT1 220 in a disabled state but without a POTS device 110 connected to IAD 130 .
- FIGS. 9 through 12 A combined inspection of FIGS. 9 through 12 shows that a threshold indicia can be used to determine if the battery supplies 220 and 230 are functional, since the maximum amplitude of the noise spikes is overwhelmingly larger when both battery supplies 220 and 230 are functional versus when VBAT1 220 is disabled, irrespective of whether a POTS device 110 is connected to IAD 130 . Similar indicia can be used to assess the condition of other IAD 130 components.
- a third embodiment of the invention involves remotely initiating a pulsing of the tip 370 and ring 372 amplifiers in a fixed frequency mode. The resultant noise is aggregated at the CODEC 240 and analyzed by the MPC 260 .
- the MPC 260 can report on some of the functionality in: the IAD batteries 220 and 230 , the SLIC 210 and associated switching circuits 386 and 373 and the associated 4-wire to 2-wire hybrid circuit 371 , and the CODEC 240 .
Abstract
Description
- The invention claims priority from U.S. Provisional Application Ser. No. 60/230,492, filed Sep. 6, 2000, and entitled “System and Method for Diagnosing a POTS Port and Circuitry”, the disclosure of which in herein incorporated by reference.
- 1. Field of the Invention
- This invention relates generally to Voice-over-Broadband (VoB) communication systems, and particularly to diagnostic assessments of the integrity of VoB systems.
- 2. Discussion of the Prior Art
- VoB systems are known in the prior art. VoB system service users are typically referred to as subscribers. FIG. 1 shows a prior
art VoB system 100, which commences at one end with traditional Plain Old Telephone Service (POTS)devices 110 that receive and transmit analog voice signals oversubscriber lines 115. An Integrated Access Device (IAD) 130 digitizes/packetizes these analog voice signals into a broadband format and integrates the resultant voice packets with additional digital data provided by other customer premise equipment such aspersonal computer 120. IAD 130 prioritizes voice packets over data packets to preserve transmitted voice signal quality. The voice and data packets are carried over the local broadband access network to an access multiplexer known as a Digital Subscriber Line Access Multiplexer (DSLAM) 140. DSLAM 140 aggregates the packets, transports voice packets to avoice gateway 150 and transports data packets to the Internet 160.Voice gateway 150 depacketizes voice packets and converts them to standard analog POTS signals for delivery via aClass 5switch 165 to the Public Switched Telephone Network (PSTN) 170. - FIG. 2 shows details of IAD130. A
POTS device 110 connected to the subscriber'sline 115 is in turn connected with a Subscriber Line Interface Circuit (SLIC) 210. The SLIC 210 has inputs for a primary battery supply (VBAT1) 220 and an auxiliary battery supply (VBAT2) 230, and has a battery switching circuit 373 (FIG. 5) for connecting toVBAT1 220 to present a high on-hook voltage, and then connecting toVBAT2 230 to present a low off-hook voltage in short-loop applications. VBAT1 and VBAT2 are connected in series by adiode 225. The diode serves as a protection device to prevent the VBAT1 (−68V) supply from going more positive than the VBAT2 (−24V) supply. This would happen if the VBAT1 supply failed, since VBAT1 voltage (−68V) is obtained by adding a −44 voltage to the VBAT2 supply. SLIC 210 passes analog POTS signals to a coder/decoder (CODEC) 240 and receives analog signals fromCODEC 240.CODEC 240 converts analog voice signals into broadband digital format, and vice versa. IAD 130 can include a digital signal processor (DSP) 250 for removing noise from the digital signals. Finally, IAD 130 employs a microprocessor controller (MPC) 260 as a central software-driven controller. MPC 260 can manipulate digital signals as necessary per the instructions of an installed software application, can receive state information from thevarious IAD 130 components, and can send digital control signals to the other components of IAD 130. In particular, MPC 260 sendsdigital control inputs 270 to SLIC 210, which control internal SLIC states. FIG. 2, for clarity, shows only one POTS port and only the processing of voice data. In practice, an IAD 130 also processes incoming digital data and includes multiple ports (typically in RJ-11 format) for connectingmultiple POTS devices 110. - Thus the
IAD 130 is a critical component of a VoB system. As VoB systems gain market share in the communications industry, IAD equipment will proliferate and it will become more important that VoB service providers have the ability to efficiently and cost effectively maintain IADs. Additionally, as users of traditional POTS devices shift to VoB service, it will become imperative, for the sake of customer relations, that VoB service providers give useful customer support regarding the low technology POTS devices. POTS devices rely on a simple two-wire loop for all their power and signaling needs and do not provide any diagnostic signaling. Thus, there is a need in the art of VoB communications for diagnostic tests on IAD equipment and POTS devices that do not require additional hardware modifications and associated costs (i.e., abide by the constraints of existing hardware designs) and do not require physical site visits for the purpose of conducting the diagnostic tests. - The invention encompasses a method for diagnosing Voice-over-Broadband circuitry including an Integrated Access Device. The method includes receiving a request to initiate diagnosis, pulsing source voltages of tip and ring amplifiers in the circuitry, aggregating signal line noise resulting from the pulsing, analyzing the aggregated noise for hallmark indicia, and reporting findings of the analysis.
- A system in accordance with the invention remotely diagnoses Voice-over-Broadband circuitry by pulsing the source voltages of the tip and ring amplifiers in the circuitry and analyzing the resultant noise for hallmark indicia. The system comprises a broadband line and an Integrated Access Device connected to the broadband line. The Integrated Access Device includes a controller connected to the broadband line, a coder/decoder connected to the controller, a Subscriber Line Interface Circuit connected to the coder/decoder, primary and auxiliary power sources connected to the Subscriber Line Interface Circuit, a Plain Old Telephone System port connected to the Subscriber Line Interface Circuit, and a signal line which interconnects the broadband line, controller, coder/decoder, Subscriber Line Interface Circuit, and Plain Old Telephone System port. The Subscriber Line Interface Circuit has tip and ring amplifiers and a switching circuit for pulsing the source voltage of the tip and ring amplifiers. The controller executes software to control the switching circuit into pulsing the source voltages of the tip and ring amplifiers in accordance with the invention.
- FIG. 1 is a high-level view of a prior art voice-over-broadband architecture;
- FIG. 2 shows additional detail of a prior art IAD;
- FIG. 3 shows hardware aspects of the present invention;
- FIG. 4 shows detail of the SLIC of FIG. 3;
- FIG. 5 is a voltage versus time graph that traces the frequency sweep pulse characteristics of one embodiment of the invention;
- FIG. 6 is noise plot for a first embodiment of the invention when a POTS device is connected to the IAD;
- FIG. 7 is a noise plot for a first embodiment of the invention when no POTS device is connected to the IAD;
- FIG. 8 is a voltage versus time graph that traces the fixed period pulse characteristics of a third embodiment of the invention;
- FIG. 9 is a noise plot for a third embodiment of the invention when both power supplies are functional and a POTS device is connected to the IAD;
- FIG. 10 is a noise plot for a third embodiment of the invention when both supplies are functional and no POTS device is connected to the IAD;
- FIG. 11 is a noise plot for a third embodiment of the invention when the primary power supply is disabled and a POTS device is connected to the IAD; and
- FIG. 12 is a noise plot for a third embodiment of the invention when the primary power supply is disabled and no POTS device is connected to the IAD.
- The invention provides a system and method for remotely conducting various diagnostic tests of an IAD's circuitry and connection integrity with a
POTS device 110. FIG. 3 shows an IAD 130 configuration including a SLIC 210, a VBAT1power supply 220, adiode 225, a VBAT2power supply 230, aCODEC 240, anoptional DSP 250, an MPC 260, anddigital control inputs 270. MPC 260 is connected to abroadband line 310, a DSLAM 140, an RS-232port 320, and anexternal computer 330. From a hardware perspective, the invention is similar to, and requires no additional hardware or design modifications over, the FIG. 2 prior art. Thus, the invention addresses the prior art need for efficient maintenance and support of IADs and associated POTS devices. -
External computer 330 is optional and is most likely to be used only to initiate the diagnostic tests. Execution of the diagnostic tests of the invention does not require external computer processing. The detailed diagnostic test instructions and the collection and analysis of test data can all be done by a computer software application installed withinIAD 130, preferably withinMPC 260. Thus, the invention can be practiced as a software-only upgrade to the priorart IAD hardware 130. - The external computer, if used, can be either: (a) located remotely and connected via the
broadband line 310 to theIAD 130; or (b) located locally and connected via the RS-232port 320. - The technique of the invention pulses the internal IAD DC power supplies (
VBAT1 220 and VBAT2 230), collects resultant noise signals within theIAD 130 and analyzes the data to determine the status of IAD circuitry and the integrity of connections with POTS devices. It should be noted that in one commercial embodiment the noise signals are measured using an AC coupled measuring system originally intended to digitize voice signals on the telephone line and block the VBAT2 battery voltage, which is present in addition to the voice signal. In other words, the measurements in that embodiment are of the AC transients (or the first derivative) of the DC pulsing. However, other embodiments can rely on DC coupled measurements and the methods and systems detailed here remain completely applicable. The only impact caused by using DC coupled noise measurements, as opposed to AC coupled noise measurements, is to the magnitude of the diagnostic threshold values, which will be discussed below. - FIG. 5 shows high level details of
SLIC 210.SLIC 210 communicates analog signals via transmitline 390 and receiveline 392 to and fromCODEC 240 and communicates via a combinedtip 394 andring 396loop 115 with aPOTS device 110. The tip-ring loop 115 is formed by aPOTS device 110 on one end connected via atip line 394 and aring line 396 to an appropriate apparatus such asIAD 130.Tip line 394 is referenced againstring line 396 and hence tip-ring loop 115 is considered a two-wire loop. In contrast, transmitline 390 is referenced against a ground line and receiveline 392 is also referenced against a ground line. Hence, a counterpart four-wire conceptual loop (not shown) is formed by the interconnection of: (a) thehybrid circuit 371; (b) one pair of wires that represent the transmitline 390 and the ground wire it is referenced to; (c) and another pair of wires that represent the receiveline 392 and the ground wire it is referenced to; and (d) a device downstream of the communication path that connects with the four wires. Thus, thehybrid circuit 371 interfaces a 2-wire loop to a 4-wire loop. This 4-to-2 arrangement is backwardly compatible with conventional POTS network architectures, which use a 2-wire loop for local transmission (i.e., near the POTS device) and use a 4-wire arrangement (one 2-wire loop for transmitting and another 2-wire loop for receiving) for long-range transmissions. Long-range wire transmissions require signal amplification which is made possible by separation of the receive and transmit analog signals. - The 4-wire to 2-wire interface has been accomplished in the prior art using a hybrid transformer.
SLIC 210 includes the 4-wire to 2-wire interface in the form ofhybrid circuit 371, which includesOp amps tip drive amplifier 370 and thering amplifier 372 have significance to the invention because the supply voltage of these two Op amps is pulsed as discussed below. -
SLIC 210 interfaces via arelay 398 to the tip andring lines relay 398 disconnects analog voice signals from the POTS device when the POTS device is “on-hook,” and connects the analog signals when “off-hook.” When the POTS device is “on-hook” the tip-ring loop alternatively connects the POTS device ring detector (not shown) to theIAD 130. -
SLIC 210 also receives digitalMPC control inputs 270, which control internal SLIC states.SLIC 210 includes a battery feedstate control circuit 386, which, per the MPC instructions, controls theswitching circuit 373 that receives battery supply voltages VBAT1 220 andVBAT2 230 and feeds the appropriate voltage to thetip drive 370 and ring drive 372 amplifiers.Switching circuit 373 has at least three connection states: (a)VBAT1 connection 380—when VBAT1 is fed to the amplifiers; (b)forward disconnection 382—when the tip and ring amplifiers are turned off; and (c)VBAT2 connection 384—when VBAT2 is fed to the amplifiers. - The invention pulses the source voltage of the
tip amplifier 370 andring amplifier 372 as follows. To conduct the diagnostic methods of the invention, MPC 260 (FIG. 3) executes a software algorithm which sends the necessary control signals onlines 270 to battery feedstate control circuit 386 which, based in part onMPC 260 inputs, makes the necessary power switching decisions for theswitching circuit 373 to make the appropriate physical connection to feed the tip and driveamplifiers - Pulsing the amplifier voltage source in various manners presents unique pulse characteristics that establish different aspects of the invention. FIG. 5 is a voltage versus
time graph 500 of one such pulse characteristic that can be used to remotely determine whether aPOTS device 110, in an on-hook state, is connected toIAD 130 and whether VBAT2 is functional. Graph 500 Y-axis 520 corresponds to the voltage applied to thetip 370 andring 372 amplifiers during diagnostic tests of the invention, and thegraph 500X-axis 510 corresponds to time. Thegraph 500 voltage cycles have fixedlength pulses 550 and increasinglylonger cycle periods 540. The voltage applied to thetip 370 andring 372 amplifiers pulses from a near zero value (obtained by placingSLIC 210 in a forward disconnect state 382) to aVBAT2 value 530. The increasinglylong cycle periods 540 represent a frequency sweep, which is central to this embodiment of the invention. - In this embodiment, the noise caused by pulsing the amplifiers is aggregated at the
CODEC 240 and, according to another aspect of the invention, analyzed by theMPC 260. Sweeping through a range of frequencies in the AC loading of the ring detector and/or ringer circuit of aPOTS device 110 presents a non-linear response at theCODEC 240. - FIGS. 6 and 7 provide contrasting examples of empirical data collected in experimental runs of this aspect of the invention. The FIG. 6
graph 600 has anx-axis 610, a y-axis 620, and a series ofspikes 630 a through 630 q representing noise data where aPOTS device 110 is connected to theIAD 130. The FIG. 7graph 700 has anx-axis 710, a y-axis 720, and a series ofspikes 730 a through 730 n representing noise data where no POTS device is connected to theIAD 130. In bothgraphs CODEC 240. This frequency sweep causes two indicia in the noise response, which the diagnostic algorithm looks for. First, as a comparison of FIG. 6 and FIG. 7 reveals, the connection of aPOTS device 110 causes noise amplitude to increase as pulse frequency decreases. Second, the connection of aPOTS device 110 causes FIG. 6 noise spikes 630 a through 630 q that have maximum amplitude below an apparent threshold of approximately 1000 linearized codec counts, while FIG. 7 noise spikes 730 a through 730 n all exceed that threshold by a factor of about 30. Thus, if the appropriate amplitude indicia are present, theMPC 260 can report that aPOTS device 110 is connected to theIAD 130. Additionally, theMPC 260 can report thatVBAT2 230 is also functional. - Not shown in FIG. 6 and in FIG. 7 is empirical data dealing with a disabled VBAT2. However, if VBAT2 were not functioning, the peak-to-peak voltage swing would drop below a predetermined threshold value. Thus, a diagnostic algorithm would assess the failure of VBAT2 by noting a peak-to-peak noise measurement that is below a defined algorithm.
- A second embodiment of the present invention is similar to the first embodiment but the
DSP 250, if present, is instructed not to filter out noise. Then, with thePOTS device 110 in an on-hook state, the same frequency sweep is remotely executed and the resultant noise is allowed to propagate all the way up to thegateway 150 or even beyond theclass 5 switch. At the remote site, presence of the necessary noise indicia indicates that all hardware components up to the SLIC 210 (including VBAT2 230) are functional. - A second variation of the amplifier voltage source pulse characteristics provides a third embodiment of the invention. FIG. 8 shows a second pulse characteristic, which can be used to remotely assess some of the functionality in: the
IAD batteries SLIC 210 and associated switchingcircuits wire hybrid circuit 371, and theCODEC 240. - It should be noted that due to the protection diode between VBAT2 and VBAT1, VBAT1 can not be tested the same way VBAT2 is tested because even if VBAT1 fails, it will still have the VBAT2 voltage level due to the protection diode.
- FIG. 8 is a
graph 800 with a y-axis 820 corresponding to the voltage applied to thetip 370 andring 372 amplifiers during diagnostic testing and with anx-axis 810 corresponding to time. Thegraph 800 pulses have fixedduration cycle periods 840 and fixedduration pulses 850. The voltage applied to thetip 370 andring 372 amplifiers pulses from a VBAT2 value 830 (obtained by placing theSLIC 210 in a VBAT2 connection 384) to a VBAT1 value 835 (obtained by placing theSLIC 210 in a VBAT1 connection 380). The fixedcycle periods 840 are a central characteristic of this embodiment in contrast to the first and second embodiments where periodicity varies. In this third embodiment, as in the first and second embodiments, noise is aggregated at theCODEC 240 and analyzed by theMPC 260. - FIGS. 9 through 12 provide contrasting examples of empirical data collected in experimental runs of this fixed-frequency embodiment of the invention.
- FIG. 9 is a graph900 having an
x-axis 910 that correlates to time, a y-axis 920 that correlates to resultant noise magnitude, and a series of noise spikes 930 a through 930 n. The empirical data of FIG. 9 has bothVBAT1 220 andVBAT2 230 in a functional state and aPOTS device 110 connected toIAD 130. - FIG. 10 is a
graph 1000 having anx-axis 1010 that correlates to time, a y-axis 1020 that correlates to resultant noise magnitude, and a series ofnoise spikes 1030 a through 1030 n. The empirical data of FIG. 10 has bothVBAT1 220 andVBAT2 230 in a functional state but without aPOTS device 110 connected toIAD 130. - FIG. 11 is a
graph 1100 having anx-axis 1110 that correlates to time, a y-axis 1120 that correlates to resultant noise magnitude, and a series ofnoise spikes 1130 a through 1130 z. The empirical data of FIG. 11 has VBAT1 220 in a disabled state and with aPOTS device 110 connected toIAD 130. - Finally, FIG. 12 is a
graph 1200 having anx-axis 1210 that correlates to time, a y-axis 1220 that correlates to resultant noise magnitude, and a series ofnoise spikes 1230 a through 1230 q. The empirical data of FIG. 12 has VBAT1 220 in a disabled state but without aPOTS device 110 connected toIAD 130. - A combined inspection of FIGS. 9 through 12 shows that a threshold indicia can be used to determine if the battery supplies220 and 230 are functional, since the maximum amplitude of the noise spikes is overwhelmingly larger when both
battery supplies VBAT1 220 is disabled, irrespective of whether aPOTS device 110 is connected toIAD 130. Similar indicia can be used to assess the condition ofother IAD 130 components. Thus, a third embodiment of the invention involves remotely initiating a pulsing of thetip 370 andring 372 amplifiers in a fixed frequency mode. The resultant noise is aggregated at theCODEC 240 and analyzed by theMPC 260. If the appropriate amplitude indicia are present, theMPC 260 can report on some of the functionality in: theIAD batteries SLIC 210 and associated switchingcircuits wire hybrid circuit 371, and theCODEC 240. - While the invention has been described herein with reference to three exemplary embodiments, they are for illustrative purposes only and not intended to be limiting. Therefore, those skilled in the art will recognize that other embodiments can be practiced without departing from the scope and spirit of the claims set forth below.
Claims (20)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/948,387 US7116637B2 (en) | 2000-09-06 | 2001-09-06 | System and method for diagnosing a POTS port |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US23049200P | 2000-09-06 | 2000-09-06 | |
US09/948,387 US7116637B2 (en) | 2000-09-06 | 2001-09-06 | System and method for diagnosing a POTS port |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020064150A1 true US20020064150A1 (en) | 2002-05-30 |
US7116637B2 US7116637B2 (en) | 2006-10-03 |
Family
ID=22865439
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/948,387 Expired - Fee Related US7116637B2 (en) | 2000-09-06 | 2001-09-06 | System and method for diagnosing a POTS port |
Country Status (4)
Country | Link |
---|---|
US (1) | US7116637B2 (en) |
EP (1) | EP1316196A2 (en) |
AU (1) | AU2001288933A1 (en) |
WO (1) | WO2002021811A2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020078225A1 (en) * | 2000-08-30 | 2002-06-20 | Pines Philip J. | System and method for measuring sample arrival rates on an asynchronous transport network |
US20070133421A1 (en) * | 2005-12-12 | 2007-06-14 | Bellsouth Intellectual Property Corporation | Digital subscriber line access multiplexer writing validation |
US20150029857A1 (en) * | 2007-01-31 | 2015-01-29 | Alcatel Lucent | Per-class scheduling with rate limiting |
US20180151187A1 (en) * | 2016-11-30 | 2018-05-31 | Microsoft Technology Licensing, Llc | Audio Signal Processing |
Citations (56)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3955052A (en) * | 1974-11-18 | 1976-05-04 | Tadiran Israel Electronics Industries Ltd. | Subscriber unit particularly useful for time-division-multiplex system |
US4087647A (en) * | 1977-05-25 | 1978-05-02 | Bell Telephone Laboratories, Incorporated | Circuit for supplying direct current to telephone station sets |
US4110636A (en) * | 1976-03-05 | 1978-08-29 | U.S. Philips Corporation | Feeding bridge |
US4203009A (en) * | 1977-08-17 | 1980-05-13 | The Post Office | Unbalanced/balanced converter circuits |
US4292478A (en) * | 1979-05-25 | 1981-09-29 | Plessey Canada Limited | Interface circuits |
US4315106A (en) * | 1979-11-28 | 1982-02-09 | International Telephone And Telegraph Corporation | Apparatus for regulating current supplied to a telephone line signal of the type employed in digital telephone systems |
US4315207A (en) * | 1980-06-20 | 1982-02-09 | Advanced Micro Devices, Inc. | Current controlled battery feed circuit |
US4388500A (en) * | 1981-02-27 | 1983-06-14 | Wescom, Inc. | Electronic hybrid |
US4419542A (en) * | 1982-05-17 | 1983-12-06 | Bell Telephone Laboratories, Incorporated | Battery feed circuit |
US4431868A (en) * | 1981-07-09 | 1984-02-14 | International Telephone And Telegraph Corporation | Solid state telephone line interface circuit with ringing capability |
US4433213A (en) * | 1981-02-06 | 1984-02-21 | Te Ka De Felten & Guilleaume Fernmeldeanlagen Gmbh | Subscriber's line circuit for telecommunications networks |
US4445006A (en) * | 1980-04-14 | 1984-04-24 | Nixdorf Computer Ag | Four-wire conversion circuit for a telephone subscriber line |
US4472608A (en) * | 1981-01-23 | 1984-09-18 | Mitel Corporation | Subscriber line interface circuit |
US4476350A (en) * | 1981-02-17 | 1984-10-09 | Bell Telephone Laboratories, Incorporated | Battery feed circuit |
US4484032A (en) * | 1982-06-07 | 1984-11-20 | Northern Telecom Limited | Active impedance transformer assisted line feed circuit |
US4514595A (en) * | 1982-06-10 | 1985-04-30 | Northern Telecom Limited | Active impedance line feed circuit |
US4543524A (en) * | 1983-07-20 | 1985-09-24 | At&T Bell Laboratories | Biased reactor maintenance termination unit |
US4612417A (en) * | 1984-07-27 | 1986-09-16 | At&T Bell Laboratories | Electronic battery feed circuit for telephone systems |
US4679224A (en) * | 1985-12-02 | 1987-07-07 | Keptel, Inc. | Telephone line testing circuit |
US4791659A (en) * | 1986-10-30 | 1988-12-13 | Domain Systems, Inc. | Remote test telephone line access system |
US4860332A (en) * | 1988-07-19 | 1989-08-22 | Hewlett-Packard Company | Apparatus for the automatic in-circuit testing of subscriber line interface circuits and method therefor |
US4937851A (en) * | 1988-07-20 | 1990-06-26 | Keptel, Inc. | Loop status verification system |
US5157708A (en) * | 1991-10-04 | 1992-10-20 | Leviton Manufacturing Co., Inc. | Portable telecommunications test instrument with line condition monitoring |
US5166925A (en) * | 1990-10-02 | 1992-11-24 | Ward Marvin W | T carrier network test apparatus and method |
US5278828A (en) * | 1992-06-04 | 1994-01-11 | Bell Communications Research, Inc. | Method and system for managing queued cells |
US5452010A (en) * | 1994-07-18 | 1995-09-19 | Tektronix, Inc. | Synchronizing digital video inputs |
US5467432A (en) * | 1992-03-13 | 1995-11-14 | Brother Kogyo Kabushiki Kaisha | Printer controller capable of operating with different operation modes based on mode-determinative codes stored in point-table memory |
US5473385A (en) * | 1994-06-07 | 1995-12-05 | Tv/Com Technologies, Inc. | Clock correction in a video data decoder using video synchronization signals |
US5528661A (en) * | 1994-02-09 | 1996-06-18 | Harris Corporation | Diagnostic mechanism for monitoring operational status of remote monitoring and test unit which controllably test and conditions subscriber line circuits |
US5533021A (en) * | 1995-02-03 | 1996-07-02 | International Business Machines Corporation | Apparatus and method for segmentation and time synchronization of the transmission of multimedia data |
US5559854A (en) * | 1993-09-20 | 1996-09-24 | Fujitsu Limited | Subscriber's line testing apparatus |
US5565924A (en) * | 1995-01-19 | 1996-10-15 | Lucent Technologies Inc. | Encoder/decoder buffer control for variable bit-rate channel |
US5598455A (en) * | 1990-09-17 | 1997-01-28 | Raychem Corporation | Alarm and test system for a digital added main line |
US5636202A (en) * | 1995-07-25 | 1997-06-03 | Lucent Technologies Inc. | Test system for detecting ISDN NT1-U interfaces |
US5761273A (en) * | 1995-12-27 | 1998-06-02 | Siemens Business Communication Systems, Inc. | Analog self-test circuitry for a trunk interface |
US5784558A (en) * | 1996-04-26 | 1998-07-21 | Integrated Network Corporation | Method and apparatus for testing of extended ISDN BRI service |
US5790523A (en) * | 1993-09-17 | 1998-08-04 | Scientific-Atlanta, Inc. | Testing facility for a broadband communications system |
US5790543A (en) * | 1995-09-25 | 1998-08-04 | Bell Atlantic Network Services, Inc. | Apparatus and method for correcting jitter in data packets |
US5793751A (en) * | 1996-03-25 | 1998-08-11 | Lucent Technologies Inc. | Apparatus and method for ISDN provision verification |
US5825849A (en) * | 1995-08-31 | 1998-10-20 | Lucent Technologies, Inc. | Loop-back test system using a suppressed ringing connection |
US5854839A (en) * | 1996-05-10 | 1998-12-29 | Lucent Technologies Inc. | Dual voltage, self-monitoring line circuit |
US5881129A (en) * | 1996-05-10 | 1999-03-09 | Chen; Robert Kuo-Wei | Self-monitoring line interface circuit |
US5883883A (en) * | 1996-10-18 | 1999-03-16 | Lucent Technologies Inc. | Apparatus and method for testing the administration of network based supplementary services |
US5892756A (en) * | 1997-01-28 | 1999-04-06 | Mtb Insights, Incorporated | Portable telecommunication network testing device |
US5909445A (en) * | 1996-08-19 | 1999-06-01 | Adtran, Inc. | Mechanism for transporting digital pots signals within framing structure of high bit rate digital local subscriber loop signals |
US5912880A (en) * | 1996-11-07 | 1999-06-15 | Northern Telecom, Limited | System and method for ATM CBR timing recovery |
US5991270A (en) * | 1996-03-19 | 1999-11-23 | Digital Lightwave, Inc. | Dynamic communication line analyzer apparatus and method |
US6002671A (en) * | 1997-09-03 | 1999-12-14 | Fluke Corporation | Test instrument for testing asymmetric digital subscriber lines |
US6014425A (en) * | 1997-02-26 | 2000-01-11 | Paradyne Corporation | Apparatus and method for qualifying telephones and other attached equipment for optimum DSL operation |
US6058162A (en) * | 1997-12-05 | 2000-05-02 | Harris Corporation | Testing of digital subscriber loops using multi-tone power ratio (MTPR) waveform |
US6091713A (en) * | 1998-04-13 | 2000-07-18 | Telcordia Technologies, Inc. | Method and system for estimating the ability of a subscriber loop to support broadband services |
US6292468B1 (en) * | 1998-12-31 | 2001-09-18 | Qwest Communications International Inc. | Method for qualifying a loop for DSL service |
US6301227B1 (en) * | 1998-08-24 | 2001-10-09 | Terayon Communication Systems, Inc. | Systems and methods for allowing transmission systems to effectively respond to automated test procedures |
US20020078225A1 (en) * | 2000-08-30 | 2002-06-20 | Pines Philip J. | System and method for measuring sample arrival rates on an asynchronous transport network |
US6574313B1 (en) * | 2000-05-12 | 2003-06-03 | Turnstone Systems, Inc. | Voice over DSL method and system for supporting a lifeline |
US6584122B1 (en) * | 1998-12-18 | 2003-06-24 | Integral Access, Inc. | Method and system for providing voice and data service |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5025457A (en) | 1989-04-21 | 1991-06-18 | Codex Corporation | Synchronizing continuous bit stream oriented terminals in a communications network |
US6282189B1 (en) | 1997-04-14 | 2001-08-28 | Next Level Communications, L.L.P. | Unified access platform for simultaneously delivering voice and cell-based services |
US6278769B1 (en) | 1998-11-25 | 2001-08-21 | Westell Technologies, Inc. | Signaling method for invoking a test mode in a network interface unit |
-
2001
- 2001-09-06 US US09/948,387 patent/US7116637B2/en not_active Expired - Fee Related
- 2001-09-06 AU AU2001288933A patent/AU2001288933A1/en not_active Abandoned
- 2001-09-06 WO PCT/US2001/028163 patent/WO2002021811A2/en active Application Filing
- 2001-09-06 EP EP01968703A patent/EP1316196A2/en not_active Withdrawn
Patent Citations (56)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3955052A (en) * | 1974-11-18 | 1976-05-04 | Tadiran Israel Electronics Industries Ltd. | Subscriber unit particularly useful for time-division-multiplex system |
US4110636A (en) * | 1976-03-05 | 1978-08-29 | U.S. Philips Corporation | Feeding bridge |
US4087647A (en) * | 1977-05-25 | 1978-05-02 | Bell Telephone Laboratories, Incorporated | Circuit for supplying direct current to telephone station sets |
US4203009A (en) * | 1977-08-17 | 1980-05-13 | The Post Office | Unbalanced/balanced converter circuits |
US4292478A (en) * | 1979-05-25 | 1981-09-29 | Plessey Canada Limited | Interface circuits |
US4315106A (en) * | 1979-11-28 | 1982-02-09 | International Telephone And Telegraph Corporation | Apparatus for regulating current supplied to a telephone line signal of the type employed in digital telephone systems |
US4445006A (en) * | 1980-04-14 | 1984-04-24 | Nixdorf Computer Ag | Four-wire conversion circuit for a telephone subscriber line |
US4315207A (en) * | 1980-06-20 | 1982-02-09 | Advanced Micro Devices, Inc. | Current controlled battery feed circuit |
US4472608A (en) * | 1981-01-23 | 1984-09-18 | Mitel Corporation | Subscriber line interface circuit |
US4433213A (en) * | 1981-02-06 | 1984-02-21 | Te Ka De Felten & Guilleaume Fernmeldeanlagen Gmbh | Subscriber's line circuit for telecommunications networks |
US4476350A (en) * | 1981-02-17 | 1984-10-09 | Bell Telephone Laboratories, Incorporated | Battery feed circuit |
US4388500A (en) * | 1981-02-27 | 1983-06-14 | Wescom, Inc. | Electronic hybrid |
US4431868A (en) * | 1981-07-09 | 1984-02-14 | International Telephone And Telegraph Corporation | Solid state telephone line interface circuit with ringing capability |
US4419542A (en) * | 1982-05-17 | 1983-12-06 | Bell Telephone Laboratories, Incorporated | Battery feed circuit |
US4484032A (en) * | 1982-06-07 | 1984-11-20 | Northern Telecom Limited | Active impedance transformer assisted line feed circuit |
US4514595A (en) * | 1982-06-10 | 1985-04-30 | Northern Telecom Limited | Active impedance line feed circuit |
US4543524A (en) * | 1983-07-20 | 1985-09-24 | At&T Bell Laboratories | Biased reactor maintenance termination unit |
US4612417A (en) * | 1984-07-27 | 1986-09-16 | At&T Bell Laboratories | Electronic battery feed circuit for telephone systems |
US4679224A (en) * | 1985-12-02 | 1987-07-07 | Keptel, Inc. | Telephone line testing circuit |
US4791659A (en) * | 1986-10-30 | 1988-12-13 | Domain Systems, Inc. | Remote test telephone line access system |
US4860332A (en) * | 1988-07-19 | 1989-08-22 | Hewlett-Packard Company | Apparatus for the automatic in-circuit testing of subscriber line interface circuits and method therefor |
US4937851A (en) * | 1988-07-20 | 1990-06-26 | Keptel, Inc. | Loop status verification system |
US5598455A (en) * | 1990-09-17 | 1997-01-28 | Raychem Corporation | Alarm and test system for a digital added main line |
US5166925A (en) * | 1990-10-02 | 1992-11-24 | Ward Marvin W | T carrier network test apparatus and method |
US5157708A (en) * | 1991-10-04 | 1992-10-20 | Leviton Manufacturing Co., Inc. | Portable telecommunications test instrument with line condition monitoring |
US5467432A (en) * | 1992-03-13 | 1995-11-14 | Brother Kogyo Kabushiki Kaisha | Printer controller capable of operating with different operation modes based on mode-determinative codes stored in point-table memory |
US5278828A (en) * | 1992-06-04 | 1994-01-11 | Bell Communications Research, Inc. | Method and system for managing queued cells |
US5790523A (en) * | 1993-09-17 | 1998-08-04 | Scientific-Atlanta, Inc. | Testing facility for a broadband communications system |
US5559854A (en) * | 1993-09-20 | 1996-09-24 | Fujitsu Limited | Subscriber's line testing apparatus |
US5528661A (en) * | 1994-02-09 | 1996-06-18 | Harris Corporation | Diagnostic mechanism for monitoring operational status of remote monitoring and test unit which controllably test and conditions subscriber line circuits |
US5473385A (en) * | 1994-06-07 | 1995-12-05 | Tv/Com Technologies, Inc. | Clock correction in a video data decoder using video synchronization signals |
US5452010A (en) * | 1994-07-18 | 1995-09-19 | Tektronix, Inc. | Synchronizing digital video inputs |
US5565924A (en) * | 1995-01-19 | 1996-10-15 | Lucent Technologies Inc. | Encoder/decoder buffer control for variable bit-rate channel |
US5533021A (en) * | 1995-02-03 | 1996-07-02 | International Business Machines Corporation | Apparatus and method for segmentation and time synchronization of the transmission of multimedia data |
US5636202A (en) * | 1995-07-25 | 1997-06-03 | Lucent Technologies Inc. | Test system for detecting ISDN NT1-U interfaces |
US5825849A (en) * | 1995-08-31 | 1998-10-20 | Lucent Technologies, Inc. | Loop-back test system using a suppressed ringing connection |
US5790543A (en) * | 1995-09-25 | 1998-08-04 | Bell Atlantic Network Services, Inc. | Apparatus and method for correcting jitter in data packets |
US5761273A (en) * | 1995-12-27 | 1998-06-02 | Siemens Business Communication Systems, Inc. | Analog self-test circuitry for a trunk interface |
US5991270A (en) * | 1996-03-19 | 1999-11-23 | Digital Lightwave, Inc. | Dynamic communication line analyzer apparatus and method |
US5793751A (en) * | 1996-03-25 | 1998-08-11 | Lucent Technologies Inc. | Apparatus and method for ISDN provision verification |
US5784558A (en) * | 1996-04-26 | 1998-07-21 | Integrated Network Corporation | Method and apparatus for testing of extended ISDN BRI service |
US5854839A (en) * | 1996-05-10 | 1998-12-29 | Lucent Technologies Inc. | Dual voltage, self-monitoring line circuit |
US5881129A (en) * | 1996-05-10 | 1999-03-09 | Chen; Robert Kuo-Wei | Self-monitoring line interface circuit |
US5909445A (en) * | 1996-08-19 | 1999-06-01 | Adtran, Inc. | Mechanism for transporting digital pots signals within framing structure of high bit rate digital local subscriber loop signals |
US5883883A (en) * | 1996-10-18 | 1999-03-16 | Lucent Technologies Inc. | Apparatus and method for testing the administration of network based supplementary services |
US5912880A (en) * | 1996-11-07 | 1999-06-15 | Northern Telecom, Limited | System and method for ATM CBR timing recovery |
US5892756A (en) * | 1997-01-28 | 1999-04-06 | Mtb Insights, Incorporated | Portable telecommunication network testing device |
US6014425A (en) * | 1997-02-26 | 2000-01-11 | Paradyne Corporation | Apparatus and method for qualifying telephones and other attached equipment for optimum DSL operation |
US6002671A (en) * | 1997-09-03 | 1999-12-14 | Fluke Corporation | Test instrument for testing asymmetric digital subscriber lines |
US6058162A (en) * | 1997-12-05 | 2000-05-02 | Harris Corporation | Testing of digital subscriber loops using multi-tone power ratio (MTPR) waveform |
US6091713A (en) * | 1998-04-13 | 2000-07-18 | Telcordia Technologies, Inc. | Method and system for estimating the ability of a subscriber loop to support broadband services |
US6301227B1 (en) * | 1998-08-24 | 2001-10-09 | Terayon Communication Systems, Inc. | Systems and methods for allowing transmission systems to effectively respond to automated test procedures |
US6584122B1 (en) * | 1998-12-18 | 2003-06-24 | Integral Access, Inc. | Method and system for providing voice and data service |
US6292468B1 (en) * | 1998-12-31 | 2001-09-18 | Qwest Communications International Inc. | Method for qualifying a loop for DSL service |
US6574313B1 (en) * | 2000-05-12 | 2003-06-03 | Turnstone Systems, Inc. | Voice over DSL method and system for supporting a lifeline |
US20020078225A1 (en) * | 2000-08-30 | 2002-06-20 | Pines Philip J. | System and method for measuring sample arrival rates on an asynchronous transport network |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020078225A1 (en) * | 2000-08-30 | 2002-06-20 | Pines Philip J. | System and method for measuring sample arrival rates on an asynchronous transport network |
US6944189B2 (en) | 2000-08-30 | 2005-09-13 | Verilink Corporation | System and method for measuring sample arrival rates on an asynchronous transport network |
US20070133421A1 (en) * | 2005-12-12 | 2007-06-14 | Bellsouth Intellectual Property Corporation | Digital subscriber line access multiplexer writing validation |
US7656811B2 (en) * | 2005-12-12 | 2010-02-02 | At&T Intellectual Property I, L.P. | Digital subscriber line access multiplexer wiring validation |
US20100098222A1 (en) * | 2005-12-12 | 2010-04-22 | Young Randy S | Digital subscriber line (dsl) access multiplexer wiring validation |
US8315176B2 (en) | 2005-12-12 | 2012-11-20 | At&T Intellectual Property I, L.P. | Digital subscriber line (DSL) access multiplexer wiring validation |
US8774015B2 (en) | 2005-12-12 | 2014-07-08 | At&T Intellectual Property I, L.P. | Digital subscriber line (DSL) access multiplexer wiring validation |
US20150029857A1 (en) * | 2007-01-31 | 2015-01-29 | Alcatel Lucent | Per-class scheduling with rate limiting |
US9258236B2 (en) * | 2007-01-31 | 2016-02-09 | Alcatel Lucent | Per-class scheduling with rate limiting |
US20180151187A1 (en) * | 2016-11-30 | 2018-05-31 | Microsoft Technology Licensing, Llc | Audio Signal Processing |
US10529352B2 (en) * | 2016-11-30 | 2020-01-07 | Microsoft Technology Licensing, Llc | Audio signal processing |
Also Published As
Publication number | Publication date |
---|---|
EP1316196A2 (en) | 2003-06-04 |
US7116637B2 (en) | 2006-10-03 |
AU2001288933A1 (en) | 2002-03-22 |
WO2002021811A3 (en) | 2003-03-13 |
WO2002021811A2 (en) | 2002-03-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7149285B2 (en) | Dynamic, automated double-ended system and method for testing and qualifying metallic telecommunication loops | |
US9148200B1 (en) | Determining power over ethernet impairment | |
EP1808000B1 (en) | Method for testing dsl capability of telephone lines | |
US7940681B2 (en) | System and method for diagnosing a cabling infrastructure using a PHY | |
US6058161A (en) | System and method for programmable telephone subscriber line test | |
CN101005529B (en) | Dsl line testing with a sealing current | |
US6169785B1 (en) | Apparatus and method for testing subscriber line | |
KR20050072414A (en) | Method and apparatus for telephone line testing | |
US7076030B2 (en) | Method and system for testing XDSL wiring | |
US7529347B2 (en) | Test system for assessing DSL capability of telephone lines | |
US7116637B2 (en) | System and method for diagnosing a POTS port | |
TWI405982B (en) | Method and apparatus for metallic line testing of a subscriber line | |
US20150103981A1 (en) | Method and System for Single-Ended Line Testing | |
EP1936875A1 (en) | System and method for diagnosing a cabling infrastructure using a PHY | |
WO2013137853A1 (en) | Common-mode based diagnostics | |
CN100531255C (en) | Method and communication device for the detection of communication equipment connected to subscriber connection line | |
US9270813B2 (en) | Pre-installation frequency domain premises wiring tests | |
KR101301280B1 (en) | Method and device for verifying switching on of a positive distribution voltage in a user connection cable comprising several strands | |
Noessing et al. | Metallic line testing solution for next generation networks | |
JPH07264291A (en) | Subscriber's line monitoring circuit and subscriber's line test equipment | |
JPH089033A (en) | Subscriber line monitor method and device therefor, and subscriber line test monitor device | |
JPS60130249A (en) | Device for diagnosing automatically subscriber line fault |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: POLYCOM, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:PINES, PHILIP J.;HENRY, BLAKE A.;REEL/FRAME:013483/0811;SIGNING DATES FROM 20021021 TO 20021022 |
|
AS | Assignment |
Owner name: VERILINK CORPORATION, ALABAMA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:POLYCOM, INC.;REEL/FRAME:014094/0224 Effective date: 20030128 |
|
AS | Assignment |
Owner name: VERSO VERILINK, LLC F/K/A WINSLOW ASSET HOLDINGS, Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VERILINK CORPORATION;REEL/FRAME:018224/0615 Effective date: 20060615 |
|
AS | Assignment |
Owner name: LAURUS MASTER FUND, LTD., NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNORS:VERSO TECHNOLOGIES, INC.;TELEMATE.NET SOFTWARE, INC.;VERSO VERILINK, LLC;REEL/FRAME:018535/0604 Effective date: 20060920 |
|
AS | Assignment |
Owner name: ADVENT IP LLC, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VERSO VERILINK, LLC;REEL/FRAME:022343/0801 Effective date: 20090302 |
|
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 4 |
|
SULP | Surcharge for late payment | ||
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 8 |
|
SULP | Surcharge for late payment |
Year of fee payment: 7 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.) |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20181003 |